/*
 * vim:noexpandtab:shiftwidth=8:tabstop=8:
 *
 * Copyright (C) Panasas Inc., 2011
 * Author: Jim Lieb jlieb@panasas.com
 *
 * contributeur : Philippe DENIEL   philippe.deniel@cea.fr
 *                Thomas LEIBOVICI  thomas.leibovici@cea.fr
 *
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 * -------------
 */

/* xattrs.c
 * VFS object (file|dir) handle object extended attributes
 */

#include "config.h"

#include <libgen.h>		/* used for 'dirname' */
#include <pthread.h>
#include <string.h>
#include <sys/types.h>
#include <ctype.h>

#include "os/xattr.h"
#include "gsh_list.h"
#include "fsal_api.h"
#include "fsal_convert.h"
#include "FSAL/fsal_commonlib.h"
#include "vfs_methods.h"
#include "common_utils.h"

typedef int (*xattr_getfunc_t) (struct fsal_obj_handle *, /* object handle */
				void *,	/* output buff */
				size_t,	/* output buff size */
				size_t *,	/* output size */
				void *arg);	/* optionnal argument */

typedef int (*xattr_setfunc_t) (struct fsal_obj_handle *, /* object handle */
				void *,	/* input buff */
				size_t,	/* input size */
				int,	/* creation flag */
				void *arg);	/* optionnal argument */

struct fsal_xattr_def {
	char xattr_name[MAXNAMLEN + 1];
	xattr_getfunc_t get_func;
	xattr_setfunc_t set_func;
	int flags;
	void *arg;
};

/*
 * DEFINE GET/SET FUNCTIONS
 */

int print_vfshandle(struct fsal_obj_handle *obj_hdl, void *buffer_addr,
		    size_t buffer_size, size_t *p_output_size, void *arg)
{
	*p_output_size =
	    snprintf(buffer_addr, buffer_size, "(not yet implemented)");

	return 0;
}				/* print_fid */

/* DEFINE HERE YOUR ATTRIBUTES LIST */

static struct fsal_xattr_def xattr_list[] = {
	{"vfshandle", print_vfshandle, NULL, XATTR_FOR_ALL | XATTR_RO, NULL},
};

#define XATTR_COUNT 1
#define XATTR_SYSTEM (INT_MAX - 1)

/* we assume that this number is < 254 */
#if (XATTR_COUNT > 254)
#error "ERROR: xattr count > 254"
#endif
/* test if an object has a given attribute */
static int do_match_type(int xattr_flag, object_file_type_t obj_type)
{
	switch (obj_type) {
	case REGULAR_FILE:
		return ((xattr_flag & XATTR_FOR_FILE) == XATTR_FOR_FILE);

	case DIRECTORY:
		return ((xattr_flag & XATTR_FOR_DIR) == XATTR_FOR_DIR);

	case SYMBOLIC_LINK:
		return ((xattr_flag & XATTR_FOR_SYMLINK) == XATTR_FOR_SYMLINK);

	default:
		return ((xattr_flag & XATTR_FOR_ALL) == XATTR_FOR_ALL);
	}
}

static int attr_is_read_only(unsigned int attr_index)
{
	if (attr_index < XATTR_COUNT) {
		if (xattr_list[attr_index].flags & XATTR_RO)
			return true;
	}
	/* else : standard xattr */
	return false;
}

static int xattr_id_to_name(int fd, unsigned int xattr_id, char *name)
{
	unsigned int index;
	unsigned int curr_idx;
	char names[MAXPATHLEN], *ptr;
	ssize_t namesize;
	size_t len = 0;

	if (xattr_id < XATTR_COUNT)
		return ERR_FSAL_INVAL;

	index = xattr_id - XATTR_COUNT;

	/* get xattrs */

	namesize = flistxattr(fd, names, sizeof(names));

	if (namesize < 0)
		return ERR_FSAL_NOENT;

	errno = 0;

	if (xattr_id == XATTR_SYSTEM) {
		strcpy(name, "system.posix_acl_access");
		return ERR_FSAL_NO_ERROR;
	}

	for (ptr = names, curr_idx = 0; ptr < names + namesize;
	     curr_idx++, ptr += len + 1) {
		len = strlen(ptr);
		if (curr_idx == index) {
			strcpy(name, ptr);
			return ERR_FSAL_NO_ERROR;
		}
	}
	return ERR_FSAL_NOENT;
}

/**
 *  return index if found,
 *  negative value on error.
 */
static int xattr_name_to_id(int fd, const char *name)
{
	unsigned int i;
	char names[MAXPATHLEN], *ptr;
	ssize_t namesize;

	/* get xattrs */

	namesize = flistxattr(fd, names, sizeof(names));

	if (namesize < 0)
		return -ERR_FSAL_NOENT;

	if (!strcmp(name, "system.posix_acl_access"))
		return XATTR_SYSTEM;

	for (ptr = names, i = 0; ptr < names + namesize;
	     i++, ptr += strlen(ptr) + 1) {
		if (!strcmp(name, ptr))
			return i + XATTR_COUNT;
	}
	return -ERR_FSAL_NOENT;
}

fsal_status_t vfs_list_ext_attrs(struct fsal_obj_handle *obj_hdl,
				 unsigned int argcookie,
				 fsal_xattrent_t *xattrs_tab,
				 unsigned int xattrs_tabsize,
				 unsigned int *p_nb_returned, int *end_of_list)
{
	unsigned int index;
	unsigned int out_index;
	unsigned int cookie = argcookie;
	struct vfs_fsal_obj_handle *obj_handle = NULL;
	int fd = -1;
	fsal_errors_t fe;

	char names[MAXPATHLEN], *ptr;
	ssize_t namesize;
	int xattr_idx;

	obj_handle =
	    container_of(obj_hdl, struct vfs_fsal_obj_handle, obj_handle);

	/* Deal with special cookie */
	if (cookie == XATTR_RW_COOKIE)
		cookie = XATTR_COUNT;

	for (index = cookie, out_index = 0;
	     index < XATTR_COUNT && out_index < xattrs_tabsize; index++) {
		if (do_match_type
		    (xattr_list[index].flags, obj_handle->obj_handle.type)) {
			/* fills an xattr entry */
			xattrs_tab[out_index].xattr_id = index;
			strlcpy(xattr_list[index].xattr_name,
				xattrs_tab[out_index].xattr_name, MAXNAMLEN+1);
			xattrs_tab[out_index].xattr_cookie = index + 1;

			/* next output slot */
			out_index++;
		}
	}

	/* save a call if output array is full */
	if (out_index == xattrs_tabsize) {
		*end_of_list = false;
		*p_nb_returned = out_index;
		return fsalstat(ERR_FSAL_NO_ERROR, 0);
	}

	/* get the path of the file in file system */
	fd = (obj_hdl->type == DIRECTORY) ?
	    vfs_fsal_open(obj_handle, O_DIRECTORY, &fe) :
	    vfs_fsal_open(obj_handle, O_RDWR, &fe);
	if (fd < 0)
		return fsalstat(fe, -fd);

	/* get xattrs */

	namesize = flistxattr(fd, names, sizeof(names));

	if (namesize >= 0) {
		size_t len = 0;

		errno = 0;

		for (ptr = names, xattr_idx = 0;
		     (ptr < names + namesize) && (out_index < xattrs_tabsize);
		     xattr_idx++, ptr += len + 1) {
			len = strlen(ptr);
			index = XATTR_COUNT + xattr_idx;

			/* skip if index is before cookie */
			if (index < cookie)
				continue;

			/* fills an xattr entry */
			xattrs_tab[out_index].xattr_id = index;
			strlcpy(xattrs_tab[out_index].xattr_name, ptr, len + 1);
			xattrs_tab[out_index].xattr_cookie = index + 1;

			/* next output slot */
			out_index++;
		}
		/* all xattrs are in the output array */
		if (ptr >= names + namesize)
			*end_of_list = true;
		else
			*end_of_list = false;
	} else			/* no xattrs */
		*end_of_list = true;

	*p_nb_returned = out_index;

	close(fd);
	return fsalstat(ERR_FSAL_NO_ERROR, 0);
}

fsal_status_t vfs_getextattr_id_by_name(struct fsal_obj_handle *obj_hdl,
					const char *xattr_name,
					unsigned int *pxattr_id)
{
	unsigned int index;
	int rc;
	bool found = false;
	struct vfs_fsal_obj_handle *obj_handle = NULL;
	int fd = -1;

	obj_handle =
	    container_of(obj_hdl, struct vfs_fsal_obj_handle, obj_handle);
	for (index = 0; index < XATTR_COUNT; index++) {
		if (!strcmp(xattr_list[index].xattr_name, xattr_name)) {
			found = true;
			break;
		}
	}

	/* search in xattrs */
	if (!found) {
		fsal_errors_t fe;
		int openflags;

		switch (obj_hdl->type) {
		case DIRECTORY:
			openflags = O_DIRECTORY;
			break;
		case SYMBOLIC_LINK:
			return fsalstat(ERR_FSAL_NOTSUPP, ENOTSUP);
		default:
			openflags = O_RDWR;
		}
		fd = vfs_fsal_open(obj_handle, openflags, &fe);
		if (fd < 0)
			return fsalstat(fe, -fd);

		errno = 0;
		rc = xattr_name_to_id(fd, xattr_name);
		if (rc < 0) {
			int minor = errno;

			close(fd);
			return fsalstat(-rc, minor);
		} else {
			index = rc;
			found = true;
		}
		close(fd);
	}

	*pxattr_id = index;
	return fsalstat(ERR_FSAL_NO_ERROR, 0);
}

fsal_status_t vfs_getextattr_value_by_id(struct fsal_obj_handle *obj_hdl,
					 unsigned int xattr_id,
					 void *buffer_addr,
					 size_t buffer_size,
					 size_t *p_output_size)
{
	struct vfs_fsal_obj_handle *obj_handle = NULL;
	int fd = -1;
	int rc = 0;

	obj_handle =
	    container_of(obj_hdl, struct vfs_fsal_obj_handle, obj_handle);

	/* check that this index match the type of entry */
	if ((xattr_id < XATTR_COUNT)
	    && !do_match_type(xattr_list[xattr_id].flags,
			      obj_handle->obj_handle.type)) {
		return fsalstat(ERR_FSAL_INVAL, 0);
	} else if (xattr_id >= XATTR_COUNT) {
		char attr_name[MAXPATHLEN];
		fsal_errors_t fe;

		fd = (obj_hdl->type == DIRECTORY) ?
			vfs_fsal_open(obj_handle, O_DIRECTORY, &fe) :
			vfs_fsal_open(obj_handle, O_RDWR, &fe);
		if (fd < 0)
			return fsalstat(fe, -fd);

		/* get the name for this attr */
		rc = xattr_id_to_name(fd, xattr_id, attr_name);
		if (rc) {
			int minor = errno;

			close(fd);
			return fsalstat(-rc, minor);
		}

		rc = fgetxattr(fd, attr_name, buffer_addr, buffer_size);
		if (rc < 0) {
			rc = errno;
			close(fd);
			return fsalstat(posix2fsal_error(rc), rc);
		}

		/* the xattr value can be a binary, or a string.
		 * trying to determine its type...
		 */
		*p_output_size = rc;

		close(fd);
		return fsalstat(ERR_FSAL_NO_ERROR, 0);
	} else {		/* built-in attr */

		/* get the value */
		rc = xattr_list[xattr_id].get_func(obj_hdl, buffer_addr,
						   buffer_size, p_output_size,
						   xattr_list[xattr_id].arg);
		return fsalstat(rc, 0);
	}
}

fsal_status_t vfs_getextattr_value(struct vfs_fsal_obj_handle *vfs_hdl,
				   int fd,
				   const char *xattr_name,
				   void *buffer_addr,
				   size_t buffer_size,
				   size_t *p_output_size)
{
	struct fsal_obj_handle *obj_hdl = &vfs_hdl->obj_handle;
	int local_fd = fd;
	int rc = 0;
	fsal_status_t st = {ERR_FSAL_NO_ERROR, 0};

	if (fd < 0) {
		int openflags;

		switch (obj_hdl->type) {
		case DIRECTORY:
			openflags = O_DIRECTORY;
			break;
		case SYMBOLIC_LINK:
			return fsalstat(ERR_FSAL_NOTSUPP, ENOTSUP);
		default:
			openflags = O_RDWR;
		}

		local_fd = vfs_fsal_open(vfs_hdl, openflags, &st.major);
		if (local_fd < 0) {
			st.minor = -local_fd;
			return st;
		}
	}

	/* is it an xattr? */
	rc = fgetxattr(local_fd, xattr_name, buffer_addr, buffer_size);
	if (rc < 0) {
		st = fsalstat(posix2fsal_error(rc), errno);
		goto out;
	}

	/* the xattr value can be a binary, or a string.
	 * trying to determine its type...
	 */
	*p_output_size = rc;

out:
	// Close the local_fd only if no fd was passed into the function and we
	// opened the file in this function explicitly.
	if (fd < 0 && local_fd > 0) {
		close(local_fd);
	}

	return st;
}


fsal_status_t vfs_getextattr_value_by_name(struct fsal_obj_handle *obj_hdl,
					   const char *xattr_name,
					   void *buffer_addr,
					   size_t buffer_size,
					   size_t *p_output_size)
{
	struct vfs_fsal_obj_handle *obj_handle = NULL;
	unsigned int index;

	obj_handle =
	    container_of(obj_hdl, struct vfs_fsal_obj_handle, obj_handle);


	/* sanity checks */
	if (!obj_hdl || !p_output_size || !buffer_addr || !xattr_name)
		return fsalstat(ERR_FSAL_FAULT, 0);


	/* look for this name */
	for (index = 0; index < XATTR_COUNT; index++) {
		if (do_match_type(xattr_list[index].flags,
				  obj_handle->obj_handle.type) &&
		    !strcmp(xattr_list[index].xattr_name, xattr_name)) {
			return vfs_getextattr_value_by_id(obj_hdl, index,
							  buffer_addr,
							  buffer_size,
							  p_output_size);
		}
	}

	return vfs_getextattr_value(obj_handle, -1 /*fd*/, xattr_name,
				    buffer_addr, buffer_size, p_output_size);
}

fsal_status_t vfs_setextattr_value(struct fsal_obj_handle *obj_hdl,
				   const char *xattr_name,
				   void *buffer_addr,
				   size_t buffer_size,
				   int create)
{
	struct vfs_fsal_obj_handle *obj_handle = NULL;
	int fd = -1;
	fsal_errors_t fe;
	int rc = 0;

	obj_handle =
	    container_of(obj_hdl, struct vfs_fsal_obj_handle, obj_handle);

	fd = (obj_hdl->type == DIRECTORY) ?
	    vfs_fsal_open(obj_handle, O_DIRECTORY, &fe) :
	    vfs_fsal_open(obj_handle, O_RDWR, &fe);
	if (fd < 0)
		return fsalstat(fe, -fd);


	if (buffer_size == 0)
		rc = fsetxattr(fd, xattr_name, "", 1,
			       create ? XATTR_CREATE : XATTR_REPLACE);
	else
		rc = fsetxattr(fd, xattr_name, (char *)buffer_addr, buffer_size,
			       create ? XATTR_CREATE : XATTR_REPLACE);

	if (rc != 0) {
		rc = errno;
		close(fd);
		return fsalstat(posix2fsal_error(rc), rc);
	}

	close(fd);

	return fsalstat(ERR_FSAL_NO_ERROR, 0);
}

fsal_status_t vfs_setextattr_value_by_id(struct fsal_obj_handle *obj_hdl,
					 unsigned int xattr_id,
					 void *buffer_addr,
					 size_t buffer_size)
{
	char name[MAXNAMLEN];
	struct vfs_fsal_obj_handle *obj_handle = NULL;
	int fd = -1;
	fsal_errors_t fe;
	int rc = 0;

	obj_handle =
	    container_of(obj_hdl, struct vfs_fsal_obj_handle, obj_handle);

	if (attr_is_read_only(xattr_id))
		return fsalstat(ERR_FSAL_PERM, 0);
	else if (xattr_id < XATTR_COUNT)
		return fsalstat(ERR_FSAL_PERM, 0);

	fd = (obj_hdl->type == DIRECTORY) ?
	    vfs_fsal_open(obj_handle, O_DIRECTORY, &fe) :
	    vfs_fsal_open(obj_handle, O_RDWR, &fe);
	if (fd < 0)
		return fsalstat(fe, -fd);

	rc = xattr_id_to_name(fd, xattr_id, name);
	if (rc) {
		int minor = errno;

		close(fd);
		return fsalstat(-rc, minor);
	}

	close(fd);

	return vfs_setextattr_value(obj_hdl, name, buffer_addr,
				    buffer_size, false);
}

fsal_status_t vfs_remove_extattr_by_id(struct fsal_obj_handle *obj_hdl,
				       unsigned int xattr_id)
{
	int rc;
	char name[MAXNAMLEN];
	struct vfs_fsal_obj_handle *obj_handle = NULL;
	int fd = -1;
	fsal_errors_t fe;

	obj_handle =
	    container_of(obj_hdl, struct vfs_fsal_obj_handle, obj_handle);
	fd = (obj_hdl->type == DIRECTORY) ?
	    vfs_fsal_open(obj_handle, O_DIRECTORY, &fe) :
	    vfs_fsal_open(obj_handle, O_RDWR, &fe);
	if (fd < 0)
		return fsalstat(fe, -fd);

	rc = xattr_id_to_name(fd, xattr_id, name);
	if (rc) {
		int minor = errno;

		close(fd);
		return fsalstat(-rc, minor);
	}

	rc = fremovexattr(fd, name);
	if (rc) {
		rc = errno;
		close(fd);
		return fsalstat(posix2fsal_error(rc), rc);
	}


	close(fd);

	return fsalstat(ERR_FSAL_NO_ERROR, 0);
}

fsal_status_t vfs_remove_extattr_by_name(struct fsal_obj_handle *obj_hdl,
					 const char *xattr_name)
{
	struct vfs_fsal_obj_handle *obj_handle = NULL;
	int fd = -1;
	int rc = 0;
	fsal_errors_t fe;

	obj_handle =
	    container_of(obj_hdl, struct vfs_fsal_obj_handle, obj_handle);

	fd = (obj_hdl->type == DIRECTORY) ?
	    vfs_fsal_open(obj_handle, O_DIRECTORY, &fe) :
	    vfs_fsal_open(obj_handle, O_RDWR, &fe);
	if (fd < 0)
		return fsalstat(fe, -fd);

	rc = fremovexattr(fd, xattr_name);
	if (rc) {
		rc = errno;
		close(fd);
		return fsalstat(posix2fsal_error(rc), rc);
	}

	close(fd);
	return fsalstat(ERR_FSAL_NO_ERROR, 0);

}
